if you type Export and see something like this:
declare -x all_proxy="socks://127.0.0.1:22000/"
Most sites assume and tell you to check your .bashrc or /etc/profile /etc/bash.bashrc which may not apply if you've unknowingly or forgot that you setup a proxy from your GUI such as Gnome.
To check in Gnome if you have a permanent proxy do the following:
System -> Settings -> Network Proxy........